On-line version ISSN 1980-5373
GONZALEZ, Cezar Henrique et al. Coupled stress-strain and electrical resistivity measurements on copper based shape memory single crystals. Mat. Res. [online]. 2004, vol.7, n.2, pp.305-311. ISSN 1980-5373. http://dx.doi.org/10.1590/S1516-14392004000200014.
Recently, electrical resistivity (ER) measurements have been done during some thermomechanical tests in copper based shape memory alloys (SMA's). In this work, single crystals of Cu-based SMA's have been studied at different temperatures to analyse the relationship between stress (s) and ER changes as a function of the strain (e). A good consistency between ER change values is observed in different experiments: thermal martensitic transformation, stress induced martensitic transformation and stress induced reorientation of martensite variants. During stress induced martensitic transformation (superelastic behaviour) and stress induced reorientation of martensite variants, a linear relationship is obtained between ER and strain as well as the absence of hys teresis. In conclusion, the present results show a direct evidence of martensite electrical resistivity anisotropy.
Keywords : shape memory effects; martensitic transformation; electrical resistivity; superelasticity.